The invention lied in the field of oscillographic or others types of data recorders.
More particularly, this invention lies in the field of braking devices for large rolls of recording medium used in oscillographs and other types of data recorders.
Still more particularly, this invention comprises an improved type of cone brake for quickly stopping a heavy roll of recording medium that has been turning at a selected angular velocity.
In the prior art, the principal means for preventing the overrun of a large heavy roll of recording paper or other recording medium in oscillographs or other types of data recorders, has been to provide a spring controlled arm pressed against the shaft, or the outer surface of the roll of paper, such that when the power is removed from the drive motor, the friction of the arm against the outer surface of the roll will be sufficient to stop the roll within a short angular rotation, and prevent overrun and tangling of the recording medium. Such friction arms have a serious disadvantage in that they provide a continuing braking effort at all times while the roll is being purposely turned. This is a source of power drain and required a higher powered motor to drive the recording system.
It is therefore the primary object of this invention to provide a simple and inexpensive brake that can be applied to a recording device, that will apply a braking effort to the shaft carrying the roll of recording medium, so as to stop the rotation of the shaft and the roll, and prevent overruning.
It is a further object of this invention to provide a type of braking effort that is controlled for a selected short period of time and that is applied simultaneously with the removal of the driving power to the recording system.